Wobble plate type compressors are well-known in patent literature, e.g., in U.S. Pat. Nos. 3,552,886, and 3,712,759. The above-mentioned compressors include a compressor housing, a front end plate which is attached to one end opening of the compressor housing and a rear end plate in the form of a cylinder head. A crank chamber and a cylinder block are defined on the compressor housing. A drive shaft extends to the interior of the crank chamber from the outside through the front end plate. A wedge-shaped cam rotor is fixed on the inner end of the drive shaft. A wobble plate is disposed on an inclined surface of the cam rotor through a thrust bearing, and also nutatably supported on a steel ball disposed on a terminal end of a ball socket, which is not rotatably disposed within a central hole of the cylinder block. The rotating motion of the wobble plate is prevented by engagement of a bevel gear fixed within the wobble plate with a bevel gear formed on the terminal end of the ball socket.
In such wobble plate compressors, the drive shaft is rotatably supported within the front end plate through a journal bearing. The drive shaft is also supported by a thrust bearing disposed between an inner end surface of the front end plate and an axial end surface of the cam rotor. However, since the drive shaft is supported in a cantilever manner, if the compressor is driven under the condition of high load, such as high discharge pressure or high suction pressure, there is a possibility of the journal bearing or thrust bearing being destroyed or separated. In particular, when the angle of the inclined surface of the cam rotor is large, the possibility of destruction or separation tends to increase. Therefore, the angle of the inclined surface of the cam rotor can not be freely selected. Furthermore, the load of compression usually acts eccentrically on the journal bearing and the thrust bearing, thereby requiring the use of a high strength bearing. Such a bearing is relatively high in cost. Also, the above eccentric load is supported by only the driving mechanism, so the deflection and offset of driving parts may easily occur, thereby making it difficult to reduce vibration and noise of the compressor.